Unnamed (northeast flank of Sugarloaf Mountain)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Cu
Ore minerals chalcocite; secondary copper mineral(s)
Gangue minerals epidote; quartz

Geographic location

Quadrangle map, 1:250,000-scale MH
Quadrangle map, 1:63,360-scale A-4
Latitude 63.1517
Longitude -145.9099
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is on the northeast flank of Sugarloaf Mountain at an elevation of 4,500 feet. It is in the NE1/4SW1/4 section 30, T. 20 S., R. 10 E., Fairbanks Meridian. It corresponds to locality 3 of Rose (1966 [ADMM GR 19]).

Geologic setting

Geologic description

This occurrence consists of copper staining and tiny veinlets of chalcocite in float of Nikolai Greenstone of Late Triassic age (Rose, 1966 [ADMM GR 19]). The basalt displays epidote alteration similar to basalt-hosted copper occurrences on Paxson Mountain (Rose and Saunders, 1965). The quartz veins are localized in north-northeast-trending joints that cut across the folded limbs of the Amphitheater syncline. The veins post-date late Jurassic deformation and are probably either Cretaceous related to regional metamorphism and granitic plutonism (Nokleberg and others, 1986) or early Tertiary (Stout, 1976).
Geologic map unit (-145.912143773473, 63.1512778131322)
Mineral deposit model Basaltic Cu (Cox and Singer, 1986; model 23).
Mineral deposit model number 23
Age of mineralization Late Triassic and Cretaceous.
Alteration of deposit The basalt displays epidote alteration; copper minerals are oxidized (Rose, 1966 [ADMM GR 19]).

Production and reserves

Indication of production None